Grind stone head vibrating device of superfinishing machine



July 29, 1969 GlsABuRo KoNno GRINT) SfIONE HEAD VIBRATING DEVICE OF SUIERFINISHING MACHINE med nec. 12, 196e 2 Sheets-Sheet 1 FIGQI FIG. 3

FIG. 2

INVENTOR.

GISABURO KONDO July 29, 1969 GisAauRo KoNDo 3,457,680v

GRIND STONE HEAD VlBRATING DEVICE OF SUPERFINISHING MACHINE Filed Dac. 12. 1966 2 Sheets-Sheet 2 FIG. 4

FIG. 6

FIG.5

INVENTOR.

GISABURO KONDO United States Patent Othce 3,457,680 Patented July 29, 1969 3,457,680 GRIND STONE HEAD VIBRATING DEVICE OF SUPERFINISHING MACHINE Gisabnro Kondo, 17-38 Katayama-cho, 4 chome, Suita-shi, Osaka-fu, Japan Filed Dec. 12, 1966, Ser. No. 601,111 Claims priority, application Japan, Dec. 10, 1965, 76,086/ 65 Int. Cl. B24b 7/02 U.S. Cl. 51-59 4 Claims ABSTRACT F THE DISCLOSURE A grind stone head Vibrating device for a superiinishing machine having right and left vibrators supporting the stone heads mounted on at least one pair of upper and ,lower round rods through air bearings. An oscillation ring is rotatably mounted and is provided with a pair of eccentric cams arranged to be equally eccentric in the opposite directions at the side of said right and left vibrators. The right and Aleft hand vibrators are retained movable back and forth in a flanked condition by springs which press the vibrators towards the cams.

The present invention relates to a device for giving vibration to the grinding stone heads in a superfnishing machine in which the right and left vibrators supporting the stone heads are mounted on at least one pair of upper and lower parallel round rods through the medium of air bearings and there is also rotatably provided an oscillation ring having a pair of eccentric cams arranged to be equally eccentric in the opposite directions to each other at the middle of the right and left Vibrators, with said vibrators being retained movable back and forth in a sandwiched condition by springs pressing both vibrators against said cams, whereby it is possible to attain frictionless high-speed vibrations with resultant improved durability of the machine and to easily obtain uniform fine surface finish and accurate roundness.

In general, an air hammer or crank mechanism is employed to provide vibration to the grind stone heads in a superiinishing machine, but this produces play at both ends of oscillation amplitude, thus inviting undesirable impact, and is also apt to produce irregularity in oscillation amplitude. Further, adoption of a flat spring supporting system for support of the vibrators tends to produce unsteadiness in linear movement and rough motion of the vibrators, thus causing the grinding stone face to impin ge upon the surface of the workpiece.

The present invention is designed to eliminate these defects. Namely, the invention, as described above, is characterized in that the right and left vibrators supporting the stone heads are mounted on at least one pair of upper and lower parallel round rods through air bearings, that there is rotatably provided an oscillation ring having a pair of eccentric cams arranged to be equally eccentric in the opposite directions at the middle of said right and left vibrators, and that said right and left vibrators are retained movable back and forth in a anked condition by springs which press said vibrators towards said cams.

Now, a preferred embodiment of the present invention will be explained with reference to the accompanying drawings.

FIGURE l is a schematic front view embodying a grind stone head vibrating device according to the present invention;

FIGURE 2 is an illustration of the oscillation ring part of the device;

FIGURE 3 is a side sectional view of the oscillation ring part;

FIGURE 4 is a side sectional View of an air bearing of the vibrator;

FIGURE 5 is a diagram illustrating the mechanism of the device according to the present invention; and

FIGURE 6 is an illustration showing a condition in which the grinding operation is conducted by the device of the present invention.

In the gures, numeral 11 denotes a frame on which are mounted a pair of upper and lower parallel round rod guides 12, 12 each having an exactly circular section, and on these round rod guides 12, 12 are supported by the right and left vibrators 13, 13 through air bearings 14, 14, respectively. It will also be seen that at the middle of said right and left vibrators 13, 13 is provided an oscillation ring 16 having a pair of eccentric cams 16', 16' which are equally deviated in the mutual-ly opposite directions on a separately provided rotatable cam shaft 15. Said both cams 16', 16' are supported in contact with the inner side of the vibrators 13, 13, while springs 17, 17 that press said lvibrators 13, 13 against said cams 16', 16 from the outer side of said vibrators 13, 13 are elastically and adjustably vsupported through adjusting screws 18, 18. At the front face of each of said vibrators 13, 13 are detachably mounted a plurality of grind stone heads 20. In FIG. 1, each vibrator 13 is shown fitted with three grind stone heads 20. Arrangement is also made such that these grind stone heads 20 act to press a shaft 22 bearing the grind stone 21 against the workpiece A. It is also to be noted that each of the eccentric cams 16', 16' mounted on the oscillation ring 16 is contacted to their respective vibrator 13 through the medium of rollers or ball bearings 25, 25, thereby to attain excellent Iwear resistance and to reduce possible surface resistance resulting from light rolling friction. In the embodiment shown in the figures, these eccentric cams 16, 16 are formed integrally and are so arranged as to produce a desired oscillation amplitude a, as shown in FIG. 2, in relation to the cam shaft 15 through cooperation of a taper shaft section 26 and a bolt 27. It should here be noted that the oscillation ring 16 is arranged detachably so as to permit free choice of oscillation amplitude by changing the oscillation rings. The air bearings 14, as shown in FIG. 4, are mounted in the shaft supports 28 secured to the rod guides 12, 12 of the right and left vibrators 13, 13 and are also so arranged as to introduce air thereinto as so required, although not shown in the gures.

The structure of the present device having been described above, now discussion will be directed to the action and effect achieved by the present device. Now, when the cam shaft 15 is turned in one direction, a pair of eccentric cams 16', 16 of the oscillation ring I16 will also be turned accordingly, and owing to their equally eccentric configuration in opposite directions, the first degree turn thereof will cause the cams 16', 16' to accelerate the right and left vibrators 13, 13 toward the outside thereof. In the next 90 degree turn, the press-supporting springs 17, 17 will be decelerated to be consequently stopped, with the ensuing 90 degree turn again causing said springs 17, 17 to be accelerated inwardly, and in the final 90 degree turn said cams 16', 16 will be declerated and stopped. Since this operation is repeatedly conducted, completely no play is produced at both ends of amplitude a of the reciprocating movements, thus permitting noiseless and impactless operation. Further, since the reactions of acceleration and deceleration cancel each other, no vibration is transmitted to the machine body at the frame 11 side. Thus, the trace of grind stone 21 on the workpiece A forms a continuous sine curve as shown in FIG. 6, which indicates improved accuracy of fine finishing.

AIt should also be noted that during said movement of the right and left vibrators 13, 13, they are supported on a pair of upper and lower parallel round rod guides 12, 12 through air bearings 14, 14, so that there results no unstable track or abrasion as observed in the conventional systems using flat springs or ball or roll slides. Since each vibrator 13 is kept on the guides 12, 12 in a oated condition by air pressure, it is free of friction and can vibrate at high speed without producing any vertical bouncing due to unsteadiness as in the conventional devices, thus greatly expanding durability of the machine. As a superfinishng is in itself an extremely line finishing process in #-(micron) range, there may be produced postnishing residue due to even a slightest error. However, according to the present device, due to the floating arrangement of the vibrators 13, 13 through air bearings 14, 14, the grind stone 21 is always easily fitted to the workpiece even in the presence of an error of several microns on the workpiece, so that the desired superinishing can be completed smoothly within the range of allowable error, whereby the surface roughness is kept under 0.2;.; and the resultant surface 'presents a mirror-like smoothness. Moreover, the powerful linear cutting operation and stable amplitude and oscillation cycle realized by the present device can completely eliminate dullness at both ends of the workpiece which has heretofore been considered as an inevitable defect in conventional supernishing processes. In addition, the surface wavyness which can not be taken olf by grinding is corrected to an advanced degree and uniform tine surface finish and accurate roundness are readily obtained over the full length of the workpiece. Also, the reciprocating motion of said pair of guides '12, 12 eliminates any possibility of impingement of the grind stone 21 against the workpiece A due to bouncing of the vibrators, thus producing little abrasion loss of the grind stone 21 and no damage on the workpiece surface.

Thus, according to the present invention, all of the defects involved in vibration of the grind stone heads in the conventional types of superiinishing machines are completely Overcome by adoption of such arrangement where the movement of the right and left vibrators is effected in a sandwiched condition by an oscillation ring having a pair of oppositely eccentric cams and the pressing springs, with said vibrators being supported by the upper and lower parallel round rods and air bearings. Thus the present device can attain more ne and accurate finishing, eliminates any abrasion loss of each part and thus greatly contributes to enhancement of durability of the entire apparatus, of which the resulting benefit is incalculable.

What is claimed is:

1. In a superlinishing machine, a grind stone head vibrating device comprising right and left vibrators each supporting at least one grind stone head on at least one pair of upper and lower parallel round rods through the medium of air bearings, and an oscillator ring having a pair of eccentric cams equally deviated in the opposite directions to each other and rotatably mounted between the right and left vibrators, both said vi-brators being movable back and forth in a sandwiched condition by springs `which press said vibrators against said cams.

2. A grind stone head vibrating device in a superlinishing machine as defined in claim 1 having a frame, said springs being adjusted by nuts in the frame.

3. A grind stone head vibrating device in a supernishing machine as defined in claim 1, wherein tubular supports are provided on the round rods, the air bearings being interposed between the supports and round rods.

4. A grind stone head vibrating device in a superlinishing machine as defined in claim 1 and ball bearings interposed between the cams and the vibrators.

References Cited UNITED STATES PATENTS 1,037,852 9/1912 Beam 51-67 2,276,611 3/1942 Connor 5l-67 2,302,105 ll/ 1942 Connor 5 l-67 LESTER M. SWINGLE, Primary Examiner 

